The Crucial Role of Dehumidification in Bridge Maintenance

The Pennsylvania Department of Transportation recently awarded Advantage Steel and Construction, LLC a $2.5M contract for the rehabilitation of the Homestead Grays Bridge and the associated West Drive Ramp located in Homestead Borough, PA.

The Bridge, which spans the Monongahela River between Homestead Borough and the Squirrel Hill neighborhood of Pittsburgh, will undergo rehabilitation construction. Advantage Steel will remove, replace, and/or install new keeper angels, bearing plates, bolts, bearing catcher plates, reconnect downspouts, clean, clear, and flush downspouts, drains, and scupper outlets, install two new tooth dams on the bridge, near the West Drive and 5th Avenue Ramps, and remove and replace various neoprene strip seals.

Advantage Steel will also oversee the subcontractors selected for the various other rehabilitation's required, such as: the removal and replacement of 3" bituminous wear course approximately, sealing transverse and longitudinal cracks in the approach pavement, cleaning and sealing concrete protective surfaces, and painting of new and existing structural steel.

Duplex 2205 stainless steel is a popular material choice for pipes in chemical processing and oil and gas applications because it combines high strength, corrosion resistance, and toughness. These properties make it well-suited to use in environments with pipes exposed to harsh chemicals and high pressure.

Recently, the construction industry started using duplex 2205 stainless steel for cavitation baffles used in dam construction and rehabilitation. A cavitation baffle is a device used to control the flow of a fluid, and it's commonly used in situations where the fluid is at high pressure and high velocity. The high strength and corrosion resistance of duplex 2205 stainless steel make it well-suited for use in these types of applications, as it can withstand the stress and wear caused by the high-pressure fluid flow. Additionally, the toughness of the material helps it to resist deformation, which is vital in maintaining the efficiency of the cavitating baffle over time.

Due to the structural makeup of duplex 2205 stainless steel, there are some best practices to keep in mind when handling it. Here are a few tips from our team:

• Watch the sequencing of welds for distortion control. Duplex 2205 stainless steel tends to distort more than regular grade 50 structural steel.
• Any Potential contamination from Carbon Steel requires pickling and passivation upon completion of welding.
  • Contamination can come from mixed steel facilities, tooling with mixed-use such as abrasives and hand tools, and fixturing.  
• During the welding process, managing the heat input through welding procedures and parameters to maintain the austenitic vs. ferritic properties of the heat-affected zone.
• "In position" welding is recommended due to the heat input described above.

This year marks the 25th Annual Women in Construction Week (WIC) celebrating and promoting the role of women in the construction industry.  WIC will be celebrated March 5-11 and is organized by the National Association of Women in Construction (NAWIC). During this week, NAWIC and construction companies typically celebrate the contributions of women in the construction industry.

Women have made significant progress in the construction industry in recent decades, although the industry remains largely male-dominated. Construction companies are increasingly recognizing the value of having more women in their workforce and are taking steps to encourage and support women in the industry. While progress may be slow, the efforts made by these companies are a step in the right direction towards a more inclusive and diverse industry.

At Advantage Steel and Construction, we celebrate the week by letting the women in our organization know we appreciate their contribution to helping our business succeed. We believe having a more diverse workforce brings a range of benefits to our company, including:

1. Increased Creativity and Innovation: We have seen different perspectives and ideas that generated a wider range of approaches and solutions to problem-solving and decision-making.
2. Improved Decision-Making: We value the different viewpoints and experiences our diversified team brings to the table. These collaborative moments have helped us make more informed and well-rounded decisions. Research has shown diverse teams are more likely to identify blind spots or biases that may be present in more homogenous teams.
3. Improved Employee Engagement and Retention: We contribute our great culture to having a diverse workforce. Our employees feel valued and included and they are engaged and committed to their work.

Overall, we find having a diverse workforce brings a range of benefits, from increased creativity and innovation to improved customer understanding and employee engagement.

The Wheeling Suspension Bridge was constructed in 1849 to extend the Cumberland Pike across the Ohio River. Built for only $250,000, the bridge consisted of four main towers, each over 130 feet above the water, connecting the main span, which stretched 1,010 feet across the river. This 1,010-foot span made the Wheeling Suspension Bridge the longest suspension bridge in the world at that time.

The bridge has a rich history, playing an essential role in the United States' westward expansion. It facilitated transportation and commerce across the Ohio River, a critical link on the National Road, which connected the eastern seaboard with the Midwest.

The Wheeling Suspension Bridge has undergone several repairs and renovations throughout its history. In 1854, a severe windstorm damaged the bridge, necessitating a reconstruction under the guidance of engineer John A. Roebling (who later designed the Brooklyn Bridge). The bridge was further strengthened in the 1870s and 1950s to accommodate increasing traffic loads. In 2019, the West Virginia Department of Transportation (WV DOT) closed the bridge to vehicular traffic due to weight limits not being followed and creating safety hazards. Other than the complete deck replacement in 1854, and a deck widening in 1956, the original structure has remained intact, with only minor repairs and additions over its 170-year life span.

In 2021, Advantage Steel and Construction was awarded the rehabilitation project for the Wheeling Suspension Bridge. This rehabilitation process involves the installation of brand-new wire cables, a complex lighting system, miscellaneous structural steel repairs, and an overall cleaning/coating of the bridge. Advantages Steel’s most significant task is replacing the existing stay and sway wire rope cables and their components. The removal and installation process requires a complex winch and pulley system. Falsework towers are also needed to string the cables up and down while supporting the existing bridge. Accurate readings of the existing cable tensions must be taken before removing the cables to ensure the new cables are properly tensioned to maintain the bridge’s structural integrity.

Advantage Steel worked alongside the Brayman Foundations team to complete a complex repair of the main cable at the northeast anchorage vault of the Wheeling Suspension Bridge. The Foundations team was challenged with drilling and installing a soldier pile and multiple anchors within extremely tight tolerances. After successfully anchoring the pile, Advantage was able to transfer the load from the existing main cable into the new pile utilizing a complex jacking system. This is just one of the many obstacles Advantage and the project team have faced on this project thus far.

Working through the documents and blueprints from the 1840s has also posed many unique challenges. Along with a 2-ton weight restriction on the bridge, Advantage Steel has had to employ some creative and unorthodox methods to reach and restore certain repair locations. All of these constraints, added with managing and coordinating work with painting and electrical subs, have kept the project team busy.

The project is currently in full swing, with cable replacement, painting, and electrical work all progressing on schedule. Almost half of the cables have already been replaced, and Advantage is looking to wrap up work on the job later this summer. Once complete, Advantage will deliver the state of West Virginia with a beautiful, newly refurbished bridge that maintains its historical value and appearance.

Insights from Jennifer McConnell's Presentation at the NASCC Conference

Earlier this year at the National Student Steel Bridge Competition (NASCC), Jennifer McConnell, a prominent researcher from the University of Delaware, delivered a captivating presentation on the corrosion of steel in design. Her talk shed light on the critical aspects of durability and design, emphasizing the importance of addressing corrosion-related challenges in infrastructure projects. In this blog post, we delve into McConnell's discussion, highlighting key insights shared during her presentation.

Understanding the Significance of Durability in Design:

McConnell kicked off her talk by emphasizing the fundamental role of durability in engineering design. Durability encompasses a structure's ability to withstand external forces, environmental conditions, and the passage of time while maintaining its intended functionality and safety. She stressed that durability is not an afterthought but an integral consideration throughout the design process. Corrosion, in particular, emerged as a prime concern that can significantly impact the durability of steel structures.

The Impacts of Corrosion on Steel:

McConnell went on to explain the detrimental effects of corrosion on steel. When steel is exposed to moisture and oxygen, a process called oxidation occurs, leading to the formation of rust. Corrosion weakens the structural integrity of steel, ultimately jeopardizing the safety and longevity of a bridge or any other steel-based infrastructure. McConnell underscored that addressing corrosion requires a comprehensive understanding of its causes, preventive measures, and mitigation strategies.

Identifying Causes of Corrosion:

McConnell highlighted various causes of corrosion that engineers must be aware of during the design phase. Factors such as moisture, salinity, air pollution, and temperature fluctuations were identified as common triggers for corrosion. She emphasized the significance of identifying the specific corrosion mechanisms prevalent in a particular region or project site to tailor preventive measures accordingly.

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Preventive Measures for Corrosion:

To combat corrosion effectively, McConnell emphasized the importance of incorporating preventive measures into the design process. Protective coatings, such as paint or specialized coatings, act as barriers against moisture and oxygen, reducing the risk of corrosion. Additionally, the use of galvanization, sacrificial anodes, and proper drainage systems were discussed as effective methods to mitigate corrosion-related issues.

Integrating Corrosion Prevention into Design:

McConnell emphasized that engineers should integrate corrosion prevention strategies right from the initial design phase. By considering factors such as material selection, environmental conditions, and maintenance requirements, engineers can significantly enhance a structure's resistance to corrosion. She stressed the importance of ongoing inspection, maintenance, and repair throughout the lifespan of a steel structure to ensure long-term durability.

The Role of Innovation:

During her presentation, McConnell also highlighted the critical role of innovation in addressing corrosion-related challenges. Researchers and engineers continually explore novel materials, coatings, and design techniques to enhance corrosion resistance. She emphasized the need for collaboration between academia, industry, and government entities to foster innovation and advance the field of corrosion prevention.

By emphasizing the significance of durability and incorporating preventive measures into the design process, engineers can effectively combat corrosion and enhance the longevity and safety of steel structures. The insights shared by McConnell serve as a valuable resource for engineers, researchers, and students, inspiring them to tackle corrosion-related challenges with innovation and expertise. As the field continues to evolve, it is through such presentations and knowledge sharing that we can build a sustainable infrastructure that stands the test of time.

Definition: The FHWA defines a fracture-critical member as a steel member either entirely in tension or with a tension element whose failure would cause either a portion or the entire bridge to collapse. A fracture-critical bridge contains one or more non-load path redundant steel tension members, components, or connections. The FHWA presents two criteria for identifying a fracture-critical bridge:

1. The bridge must have one or more steel members, components, or connections in tension. These loading conditions may include tensile forces and flexure. Load analysis may indicate that some members experience a stress reversal (varies from tension to compression) under various loads. Such members shall be included under these criteria.

2. The bridge must have no load path redundancy, in which no other structural elements can carry the load if a main load-carrying member fails. A bridge must have two or fewer load paths to be defined as nonload paths redundant.

On a typical day in downtown Pittsburgh, as commuters traverse the Rachel Carson Bridge bound for places of business and entertainment, little thought is paid to what is happening among the beams, eyebars, and girders that make up the world-famous river crossing. With every passer-by, the bridge undergoes compression, tension, flexion, and limitless other forces passing through its structure.

As these forces work through the bridge, they follow what is known as a "load path." Invisible forces caused by each car travel like electricity through steel tension members, components, or connections. While each is important, only some receive the designation "Fracture Critical Members" (FCMs). An FCM is a component of the bridge that, should it fail, would cause either a portion or the entire bridge to collapse. Key to the identification of an FCM is a need for more redundancy. Should the main component of a bridge not have redundant load paths to carry the forces of cars traveling over it, this principal component would be considered fracture-critical. The term first came into existence in the late 60s after the collapse of the Silver Bridge in Kanauga, OH. The famous collapse was due to a failure in a suspension chain that supported the bridge's main span, which would today be identified as fracture-critical.

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Fracture-critical members are comprised of similarly named fracture-critical materials, which are special metals that have been created with higher strength specifications than the standard. Given the severity of consequences should one of these components fail, the FHWA and AASHTO have strict guidelines governing how fracture-critical materials and members are to be handled.

Over decades, FCMs in high-traffic areas will bear the load of hundreds of thousands of cars, rainstorms, high heat, freezing temperatures, and more. As fatigue sets in, eventually, they will need to be rehabilitated or replaced to maintain their strength. The complex process of rehabbing the most critical components of a bridge structure is not a task that many fabrication shops are willing to take on. It is a niche offering that can be difficult to find certified fabrication shops. Typically, this kind of work is only provided by large-scale fabricators due to the cumbersome nature of adhering to the many regulations and strict quality control measures associated with fracture critical materials and members.

At Advantage Steel and Construction, we are proud to have earned our FCM certifications and are willing to work on these projects in our fabrication shop. Certified by the American Institute of Steel Construction, our Saxonburg, PA shop adheres to the rigid set of quality control measures required of fracture critical materials to ensure that finished members from our shop are stronger than needed for where they will be placed.

Let's revisit the Rachel Carson Bridge in Pittsburgh for an example from the field. Advantage Steel and Construction worked with general contractor Brayman Construction Corporation to rehabilitate the staple Pittsburgh landmark from 2019 to 2020. The project's scope involved rehabbing or replacing components across the entire bridge. The accelerating effects of aging had brought rust into the interior of the main stiffening girders, which are three vertical web plates connected with a bottom flange plate. The leading cause of damage was water ingress from the nearby curb, which, over time, caused the bridge to rust from the inside out.

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In addition to sealing this water ingress location, we repaired the stringer connections, floor beam connections, stiffening girders, and sidewalk brackets. Perhaps most important was the work on the bridge's tie-down system and anchors. These components have fracture critical designations, meaning that if one were to show signs of failure, the bridge would be entirely shut down. To restore strength to the aging bridge, we fabricated and installed four new tie-downs and anchors to replace or reinforce the old ones. All fracture critical materials were made of Grade 50 structural steel and manufactured at Advantage's shop. The FCMs used on this project adhered to stringent specifications, meaning the steel was rolled to a particular criterion, making it extremely hard and much stronger than needed. Rigidity and structural integrity were restored by adding this new material to the anchors.

On the way to rehabilitating the bridge, primary consideration was given to historical preservation. Putting a modern spin on old construction practices, we could maintain the bridge's original look without sacrificing strength.

The work done on this bridge by the crews at Advantage Steel and Construction earned the project the 2021 ASHE-Pittsburgh Annual Outstanding Highway Engineering Award.

Today, we continue to work involving fracture-critical materials and members on the Sherman Minton Bridge, a double-decked bridge connecting Louisville, KY, to New Albany, IN. The Sherman Minton Bridge is a critical regional artery, seeing 70,000 cars pass over it daily. We worked with Kokosing, the General Contractor, to fabricate new fracture-critical designated cable brackets. The brackets, which play a crucial role in connecting and anchoring the bridge cables, are an item that many larger shops would pass on due to concerns over cost-effectiveness, and smaller shops typically need more capabilities to work with. We can offer unique value on this project due to its ability to deliver big shop value at the scale demanded by the project.

According to data published by the Department of Transportation, over 18,000 bridges across the nation are designated as having fracture-critical members. With American infrastructure deteriorating, shops that can rehabilitate these structures will be vitally important. Advantage Steel and Construction can meet the growing demand for FCM fabrication and rehabilitation at a unique scale, offering cost-effective and quality work to projects big and small.

Dehumidification on Pittsburgh's 10th Street Bridge: A Triumph in Specialized Bridge Maintenance

Nestled in the heart of Pittsburgh, the 10th Street Bridge is more than just a conduit for commuters; it's a historical landmark and a symbol of our city's resilience and engineering expertise. However, maintaining such an iconic structure is no small feat, especially when it comes to preserving its vital components like the cables.

Understanding the Dehumidification Process

Dehumidification is essential for combating the primary enemy of steel in bridge cables: moisture. The presence of humidity can accelerate corrosion, weakening the structural integrity of the cables. Our dehumidification maintenance process on the 10th Street Bridge involved several key steps to combat this issue effectively.

Environmental Assessment: First, our team conducted a thorough assessment of the bridge's environment. Understanding local weather patterns, humidity levels, and potential moisture sources provided us with a clear picture of the environmental impact we needed to keep an eye on when providing maintenance and making recommendations for future services.

Inspect Current Dehumidification Systems: Next, we inspected the specialized dehumidification systems around the bridge's cables. These systems work by creating a dry, controlled environment, preventing moisture from reaching the steel cables. The inspection process required precision and care, ensuring every section of the cable was protected and not compromised.

Continuous Monitoring: After installation, the system's effectiveness is continuously monitored. Sensors are placed to track humidity levels, ensuring they remain at a level where corrosion is significantly slowed down. This monitoring is crucial for adapting the system to changing environmental conditions.

Maintenance and Adjustments: Regular maintenance of the dehumidification system is vital. Routine inspections and adjustments to the system will ensure optimal performance, adapting to changes in the bridge's structural needs or environmental factors.

Why This Is a Specialized Job

Dehumidification maintenance on such a large scale is not a common skill. It requires a deep understanding of structural engineering, meteorology, and material science. Working on an iconic structure like the 10th Street Bridge adds layers of complexity, given its size, age, and design.

Navigating Heights and Structures: The task involves working at daunting heights, often suspended over the river. This requires not only courage but also specialized training in safety and maneuvering.

Complex Installation: Fitting dehumidification systems onto the intricate cable structures of the bridge demands precision engineering. Our team must ensure that every part of the cable is enveloped in a controlled environment, a task that requires both meticulous planning and dexterity.

Safety First: Ensuring the safety of our team and the structure is paramount. This means adhering to stringent safety protocols, using state-of-the-art equipment, and continuously training our personnel in the latest safety practices.

Adapting to Environmental Conditions: Working outdoors on a bridge means our team faces varying weather conditions, from intense sunlight to strong winds. Adapting to these conditions while maintaining focus and precision is a skill honed through experience.

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Logistical Coordination: The process involves coordinating with various stakeholders, including city officials, traffic management, and environmental agencies, to ensure minimal disruption and maximum efficiency.

The dehumidification maintenance performed by Advantage Steel and Construction on the 10th Street Bridge is a perfect example of our commitment to bridge maintenance and safety. This highly specialized job, though not widely known, plays a crucial role in preserving the structural integrity of bridges. As we continue our work, we remain dedicated to applying our expertise to maintain and extend the life of historical infrastructures like the 10th Street Bridge, safeguarding their longevity for future generations.

The rehabilitation of the Wheeling Suspension Bridge, a structure of rich historical significance, is nearing its completion. Advantage Steel & Construction commenced work on this iconic bridge shortly after being awarded the contract in 2021.

The most significant part of this rehabilitation work involved the meticulous removal of each of the existing 72 stay cables, 31 backstay cables, and 12 sway cables. Advantage Steel personnel carefully put together an intricate removal and installation process, which required the use of multiple winch systems, falsework towers, sky climbers, and of course, manpower. Prior to removal, Advantage personnel had to accurately record the existing tension in each cable using large-scale dynamometers, ensuring that what was taken off the bridge was replaced in kind without compromising the bridge’s structural integrity.

In addition to replacing the stay and sway cables, the anchorage for one of the bridge’s main structural components had experienced severe corrosion and needed replacement. With the help of Tunstall Engineering, our team members came up with a falsework plan to temporarily support the main stay cables load and transfer it to a brand-new anchorage point drilled for and placed by the Brayman Construction team.

Once the bridge’s structural components were replaced, it was painted, and lights were strung up on the cables and towers to really bring this historic landmark back to life.

As the project neared completion, some additional repairs were added to the scope of the work as Advantage crews discovered that years of exposure to the elements had caused one of the large timber members of the truss system to experience a significant amount of rotting. They brought this to the attention of the DOT, and upon review, it was decided that this member would indeed need to be removed and replaced. Precise field measurements were taken, and after undergoing a drying period, the new timber member was shipped to the job site. The existing compromised member was successfully removed at the beginning of 2024, and the new member was hoisted over the truss's edge, carefully moved into place, and secured into its proper position.

Finally, to close out the job, the northeast anchorage housing will be rebuilt. Due to the placement of the moved main cable to its new anchorage pile, the cable is now in direct line with where the anchorage housing originally sat. Because of its historical nature, it was imperative to the DOT that the original stones be used to rebuild the housing, so Advantage Steel devised a plan to pour a concrete wall that encased the main cable and cut the original stones at the face to be mortared to the newly poured wall. This will successfully preserve the original look of the housing while keeping it structurally sound.

The Wheeling Suspension Bridge Project is a testament to Advantage Steel & Construction’s expertise and problem-solving skills. It has presented unique challenges that have tested our ability to develop complex plans and procedures while still requiring us to think on the fly when faced with new variables. We are proud of our team's adaptability and dedication to delivering a successful project.

In October 2023, Advantage Steel & Construction completed the rehabilitation of the E. H. Swindell Bridge, a critical infrastructure project for the City of Pittsburgh. The Swindell Bridge, an iconic structure connecting the neighborhoods of Perry Hilltop, Northview Heights, and Spring Hill-City View, has long been a vital link across the East Street Valley. Originally constructed in 1930, this bridge has stood the test of time, though not without its challenges.

Named after E. H. Swindell, a notable Pittsburgh businessman and early advocate for the bridge, the Swindell Bridge is the longest bridge in Pittsburgh that does not span a river. Over the years, it has undergone several rehabilitation projects, but by 2009, it was rated as being in “Poor Condition” by PennDOT. Fast forward to 2023, Advantage Steel & Construction stepped in as the general contractor, tasked with performing critical repairs and fabrication work to extend the life of this historic bridge.

A Complex Undertaking: The 2023 Rehabilitation

The 2023 rehabilitation project was no small feat. Advantage Steel & Construction took on the challenge of fabricating and repairing the steel stringers—vital components that support the bridge. These stringers are crucial for the stability and integrity of the bridge.

To ensure the safety and efficiency of the project, the Advantage crew implemented a series of strategic measures. They installed a Quick-Deck platform under the bridge deck, allowing access to the repair areas. HP beams were used to temporarily support the stringers during the replacement of beam ends. The team also meticulously cleaned and painted the floorbeams, installed new stiffeners, and replaced the existing floorbeams. Every repair was cleaned, primed, and painted to ensure longevity, and the roadway was patched with High Early concrete to restore its surface.

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Key Construction Elements

• Quick-Deck Platform Installation: Provided safe and efficient access to the bridge’s underbelly.
• Steel Erection & Repairs: Involved intricate work on steel stringers and floorbeams, including fabrication and installation of repair material.
• Girder/Floorbeam Cleaning & Repainting: Ensured the structural integrity and aesthetic appeal of the bridge.
• Temporary Support Systems: Used HP beams for stringer support during critical repair phases.

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Beyond the Repairs: The Impact on Pittsburgh

By handling both the fabrication and repairs in-house, Advantage Steel & Construction was able to expedite the project timeline, allowing the Swindell Bridge to reopen ahead of schedule. This early reopening was a significant win for the local community, reducing traffic disruptions and reconnecting neighborhoods sooner than expected.

The completion of the E. H. Swindell Bridge rehabilitation not only preserves a piece of Pittsburgh’s history but also reinforces the city’s commitment to maintaining and enhancing its infrastructure. Advantage Steel & Construction is honored to have played a pivotal role in this important project, ensuring that the Swindell Bridge continues to serve the Pittsburgh community for years to come.

This project stands as a testament to the expertise and dedication of the Advantage Steel & Construction team, showcasing their ability to tackle complex infrastructure challenges with precision and efficiency. As Pittsburgh continues to grow and evolve, Advantage Steel & Construction remains committed to supporting the city’s infrastructure needs with unparalleled skill and craftsmanship.